There's a Cevat Yerli
Q&A on IGN talking with the Crytek CEO about a variety of topics. One
interesting bit, as pointed out by
Gamasutra
(thanks Mike Martinez), is his elaboration on his previous assertions about the impact of
PC piracy on sales of Crysis, as his guestimates at piracy rations are pretty
darned steep:

The other critique outside Crytek was the fact that the PC
industry is really, at the moment, I would say the most intensely pirated market
ever. It's crazy how the ratio between sales to piracy is probably 1 to 15 to 1
to 20 right now. For one sale there are 15 to 20 pirates and pirate versions,
and that's a big shame for the PC industry. I hope with Warhead I hope we
improve the situation, but at the same time it may have an impact on [our] PC
exclusivity in the future.

However it's unrealistic to believe that this is a small number given historical piracy statistics.

Except those historical piracy statistics were just as unreliable the statistics we have today. There has never been, nor will there ever be, a reliable way to measure the impact of piracy on profits.

But with a primarily single player game they can't take it too far and ignore pirates entirely; without any meaningful protection you end up with a tragedy of the commons situation.

There have been many single-player games that have done well in spite of piracy. Blizzard's games, Relic's games, Bethesda's games, Infinity Ward's games. Were these all pirated heavily? Of course. That didn't stop them from making enough profits to fund their next game.

To these people it's a good game, and there's no meaningful reason to believe that pirates have a different taste.

The difference is that pirates can actually play games before they buy them.